Considerable information exists about the metabolism of prostaglandins in the gastrointestinal tract of adults. Surprisingly, very little is known about similar processes during early post-natal development, especially in view of the presence of protaglandins in milk. The proposed studies will therefore concentrate on comparison of developmental changes in prostaglandin metabolism in the gastrointestinal tract with emphasis on the processing of orally administered prostaglandins and the role of prostaglandins in the immature gastrointestinal tract in normal and pathological conditions. OBJECTIVES: 1) To determine the prostaglandin content, synthesis, and degradative capacity of the gastrointestinal tract in rats at various developmental stages, tissue preparations will be incubated with radiolabeled arachidonic acid and prostaglandin, followed by isolation of the formed products of prostaglandin synthesis and degradation respectively. 2) To characterize the processing of orally administered prostaglandin by the rat gastrointestinal tract, studies will be performed with radiolabeled prostaglandin with subsequent analysis of intact prostaglandin and metabolites in the gastrointestinal tract and peripheral organs. 3) To examine the significance and metabolism of prostaglandins in the gastrointestinal tract in an experimental animal model of neonatal necrotizing enterocolitis (NEC). Evaluation of prostaglandin metabolism in the immature gastrointestinal tract will allow a more complete understanding of the physiology of the newborn intestine and may provide insight into some of the medical problems relating to nutrition and the gastrointestinal tract in the premature neonate.